[Dnsmasq-discuss] iPhones not getting proper dhcp

Thu Aug 24 21:47:28 BST 2017

Greetings -

I have an issue in our office where the iPhones are not able to receive 
an internet connection through our wireless access point.  I believe I 
have it narrowed it down to a DHCP issue by looking at how the Android 
phones connect and looking at the log files, but am not sure of the root 
problem and how to resolve it.

The appropriate network map is:
    Network Gateway is at  192.168.112.11   (a pfSense firewall router)
    Wireless Access Point is at  192.168.112.12   (an Ubiquiti UniFi 
AP-AC-Pro)
    Dnsmasq on CentOS VM  is at  192.168.112.51

Dnsmasq has static addresses assigned to desktop systems in the office, 
but provides dhcp addresses to wireless clients.  The dnsmasq 
configuration is:

bogus-priv
filterwin2k
strict-order
server=/pfgateway.mei.lan/192.168.112.11
local=/mei.lan/
expand-hosts
domain=mei.lan
dhcp-range=192.168.112.100,192.168.112.199,1h
# Desktop Systems
dhcp-host=jab-prec3610,192.168.112.101,24h
dhcp-host=gwg-lat7480,192.168.112.104,24h
dhcp-host=jsn-lat6420,192.168.112.105,24h
dhcp-host=rdr-lat6540,192.168.112.106,24h
dhcp-host=jks-lat6540,192.168.112.107,24h
# Field Laptops
dhcp-host=jks-e6500,192.168.112.121,24h
dhcp-host=rdr-d830,192.168.112.122,24h
# Wireless Access Point
dhcp-host=04:18:d6:c0:b3:2e,192.168.112.12,24h
dhcp-option=3,192.168.112.11
dhcp-option=44,192.168.112.50     # Wins (samba) Server is on Sequoia
dhcp-option=45,192.168.112.50     # Wins (samba) Server is on Sequoia
dhcp-option=46,8
dhcp-option=vendor:MSFT,2,1i
log-facility=/var/log/dsnmasq.log
log-dhcp

Looking at the Ubiquiti Access Point web interface of the clients as 
they connect it shows Android devices get an IP address in the range of 
192.168.112/24 as expected.  However, iPhone clients get an IP address 
such as 169.254.55.140.  I assumed from this that there is some issue 
with getting a proper IP address from the dhcp server, and 
169.254.55.xxx is a default network for the Apple devices.  So the 
iPhones connect to the wireless access point, but they will not have an 
internet connection.

So I pulled the logs from dnsmasq showing an Android phone connecting, 
an iPhone connecting, and also the Apple Watch that is tethered to the 
iPhone.  From this I can see that the iPhone is being offered the 
address of 192.168.112.112.  I have checked the dnsmasq.leases file and 
can see that this address is not used elsewhere on the network.  The 
logs are listed below.

Android

Aug 24 11:51:09 dnsmasq-dhcp[26073]: 2392689489 Available DHCP range: 
192.168.112.100 -- 192.168.112.199

Aug 24 11:51:09 dnsmasq-dhcp[26073]: 2392689489 client provides name: 
android-66f1326de74eb90e

Aug 24 11:51:09 dnsmasq-dhcp[26073]: 2392689489 Vendor class: dhcpcd-5.5.6

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 DHCPDISCOVER(eth0) 
d0:22:be:cc:4c:57

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 DHCPOFFER(eth0) 
192.168.112.109 d0:22:be:cc:4c:57

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 requested options: 
1:netmask, 33:static-route, 3:router, 6:dns-server,

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 requested options: 
15:domain-name, 26:mtu, 28:broadcast, 51:lease-time,

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 requested options: 
58:T1, 59:T2

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 tags: eth0

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 next server: 192.168.112.51

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:1 option: 
53:message-type02

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:4 option: 
54:server-identifier192.168.112.51

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:4 option: 
51:lease-time00:00:0e:10

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:4 option: 
58:T100:00:07:08

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:4 option: 
59:T200:00:0c:4e

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:4 
option:1:netmask255.255.255.0

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:4 option: 
28:broadcast192.168.112.255

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:4 
option:6:dns-server192.168.112.51

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:7 option: 
15:domain-namemei.lan

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:4 
option:3:router192.168.112.11

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 Available DHCP range: 
192.168.112.100 -- 192.168.112.199

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 client provides name: 
android-66f1326de74eb90e

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 Vendor class: dhcpcd-5.5.6

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 DHCPREQUEST(eth0) 
192.168.112.109 d0:22:be:cc:4c:57

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 DHCPACK(eth0) 
192.168.112.109 d0:22:be:cc:4c:57 android-66f1326de74eb90e

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 requested options: 
1:netmask, 33:static-route, 3:router, 6:dns-server,

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 requested options: 
15:domain-name, 26:mtu, 28:broadcast, 51:lease-time,

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 requested options: 
58:T1, 59:T2

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 tags: eth0

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 next server: 192.168.112.51

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:1 option: 
53:message-type05

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:4 option: 
54:server-identifier192.168.112.51

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:4 option: 
51:lease-time00:00:0e:10

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:4 option: 
58:T100:00:07:08

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:4 option: 
59:T200:00:0c:4e

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:4 
option:1:netmask255.255.255.0

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:4 option: 
28:broadcast192.168.112.255

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:4 
option:6:dns-server192.168.112.51

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:7 option: 
15:domain-namemei.lan

Aug 24 11:51:12 dnsmasq-dhcp[26073]: 2392689489 sent size:4 
option:3:router192.168.112.11

iPhone

Aug 24 11:51:14 dnsmasq-dhcp[26073]: 3282959948 Available DHCP range: 
192.168.112.100 -- 192.168.112.199

Aug 24 11:51:14 dnsmasq-dhcp[26073]: 3282959948 client provides name: 
Robbanks-iPhone

Aug 24 11:51:17 dnsmasq-dhcp[26073]: 3282959948 DHCPDISCOVER(eth0) 
e0:c7:67:89:d1:0c

Aug 24 11:51:17 dnsmasq-dhcp[26073]: 3282959948 DHCPOFFER(eth0) 
192.168.112.112 e0:c7:67:89:d1:0c

Aug 24 11:51:17 dnsmasq-dhcp[26073]: 3282959948 requested options: 
1:netmask, 121:classless-static-route, 3:router,

Aug 24 11:51:17 dnsmasq-dhcp[26073]: 3282959948 requested options: 
6:dns-server, 15:domain-name, 119:domain-search,

Aug 24 11:51:17 dnsmasq-dhcp[26073]: 3282959948 requested options: 252

Aug 24 11:51:17 dnsmasq-dhcp[26073]: 3282959948 tags: eth0

Aug 24 11:51:17 dnsmasq-dhcp[26073]: 3282959948 next server: 192.168.112.51

Aug 24 11:51:17 dnsmasq-dhcp[26073]: 3282959948 sent size:1 option: 
53:message-type02

Aug 24 11:51:17 dnsmasq-dhcp[26073]: 3282959948 sent size:4 option: 
54:server-identifier192.168.112.51

Aug 24 11:51:17 dnsmasq-dhcp[26073]: 3282959948 sent size:4 option: 
51:lease-time00:00:0e:10

Aug 24 11:51:17 dnsmasq-dhcp[26073]: 3282959948 sent size:4 option: 
58:T100:00:07:08

Aug 24 11:51:17 dnsmasq-dhcp[26073]: 3282959948 sent size:4 option: 
59:T200:00:0c:4e

Aug 24 11:51:17 dnsmasq-dhcp[26073]: 3282959948 sent size:4 
option:1:netmask255.255.255.0

Aug 24 11:51:17 dnsmasq-dhcp[26073]: 3282959948 sent size:4 option: 
28:broadcast192.168.112.255

Aug 24 11:51:17 dnsmasq-dhcp[26073]: 3282959948 sent size:4 
option:6:dns-server192.168.112.51

Aug 24 11:51:17 dnsmasq-dhcp[26073]: 3282959948 sent size:7 option: 
15:domain-namemei.lan

Aug 24 11:51:17 dnsmasq-dhcp[26073]: 3282959948 sent size:4 
option:3:router192.168.112.11

Apple Watch (linked to above iPhone)

Aug 24 11:59:04 dnsmasq-dhcp[26073]: 2153487984 Available DHCP range: 
192.168.112.100 -- 192.168.112.199

Aug 24 11:59:04 dnsmasq-dhcp[26073]: 2153487984 client provides name: 
RobynsApleWatch

Aug 24 11:59:07 dnsmasq-dhcp[26073]: 2153487984 DHCPDISCOVER(eth0) 
c0:ce:cd:dc:24:b4

Aug 24 11:59:07 dnsmasq-dhcp[26073]: 2153487984 DHCPOFFER(eth0) 
192.168.112.127 c0:ce:cd:dc:24:b4

Aug 24 11:59:07 dnsmasq-dhcp[26073]: 2153487984 requested options: 
1:netmask, 121:classless-static-route, 3:router,

Aug 24 11:59:07 dnsmasq-dhcp[26073]: 2153487984 requested options: 
6:dns-server, 15:domain-name, 119:domain-search,

Aug 24 11:59:07 dnsmasq-dhcp[26073]: 2153487984 requested options: 252

Aug 24 11:59:07 dnsmasq-dhcp[26073]: 2153487984 tags: eth0

Aug 24 11:59:07 dnsmasq-dhcp[26073]: 2153487984 next server: 192.168.112.51

Aug 24 11:59:07 dnsmasq-dhcp[26073]: 2153487984 sent size:1 option: 
53:message-type02

Aug 24 11:59:07 dnsmasq-dhcp[26073]: 2153487984 sent size:4 option: 
54:server-identifier192.168.112.51

Aug 24 11:59:07 dnsmasq-dhcp[26073]: 2153487984 sent size:4 option: 
51:lease-time00:00:0e:10

Aug 24 11:59:07 dnsmasq-dhcp[26073]: 2153487984 sent size:4 option: 
58:T100:00:07:08

Aug 24 11:59:07 dnsmasq-dhcp[26073]: 2153487984 sent size:4 option: 
59:T200:00:0c:4e

Aug 24 11:59:07 dnsmasq-dhcp[26073]: 2153487984 sent size:4 
option:1:netmask255.255.255.0

Aug 24 11:59:07 dnsmasq-dhcp[26073]: 2153487984 sent size:4 option: 
28:broadcast192.168.112.255

Aug 24 11:59:07 dnsmasq-dhcp[26073]: 2153487984 sent size:4 
option:6:dns-server192.168.112.51

Aug 24 11:59:07 dnsmasq-dhcp[26073]: 2153487984 sent size:7 option: 
15:domain-namemei.lan

Aug 24 11:59:07 dnsmasq-dhcp[26073]: 2153487984 sent size:4 
option:3:router192.168.112.11

I want to say that this is an Apple iPhone issue because it is occurring 
only with the iPhones in the office, and not anything else.  However, I 
don't know where to look any further and am hoping someone can give me 
some pointers on further diagnosing this, or if an obvious solution is 
available that I am unaware of.  Thanks.

Jeff

-- 

Jeff Boyce
Meridian Environmental